Support to date, datetime and time inputs.

I changed `DateTimeInput` to support the new HTML5 form helpers that
comes with Rails 4 (`date_input`, `datetime_input` and `time_input`)
instead of rendering datetime selects:

For example, this input:
```erb
<%= f.input :born_on, as: :date %>
```
Will render:
```html
<input id="user_born_on" name="user[born_on]" type="date" />
```

Datetime selects are still present, but only when HTML5 compatibility
is disabled. It's also possible to render selects even with HTML5 on,
by setting the `html5` option to false.

If we wanted to use an old date select on the example above, we should do:
```erb
<%= f.input :born_on, as: :date, html5: false %>
```

Closes #844.
Assert `input` tags instead of `select` for datetime attributes.
Do not assert `required` HTML5 attribute when HTML5 compatibility is disabled.
Add a CHANGELOG entry regarding datetime inputs.
Remove unecessary `enable` call.
Merge branch 'master' into vs-html5-datetime-inputs

Conflicts:
	CHANGELOG.md
Use classic datetime selects unless HTML5 is explicitly enabled.
Just `input_options[:html5]` is enough.
Fix mapping table regarding datetime columns.
Allow not including input wrapper class

There could be faulty behavior when setting checkbox or radio class
to the input wrapper, as in Bootstrap 3.

Fixes #930
Merge pull request #933 from plataformatec/lc-include-input-wrapper-class-config

Allow not including input wrapper class
Merge branch 'master' into vs-html5-datetime-inputs

Conflicts:
	CHANGELOG.md
Use Rails 4.0.1
Make sure label text is escaped if it is not safe

Signed-off-by: Rafael Mendonça França <rafaelmfranca@gmail.com>
Make sure hint text is escaped if it is not safe

Signed-off-by: Rafael Mendonça França <rafaelmfranca@gmail.com>
Make sure error_prefix option is escaped if it is not safe

Signed-off-by: Rafael Mendonça França <rafaelmfranca@gmail.com>
Release 3.0.1
Merge branch '3-0-1'

Conflicts:
	CHANGELOG.md
input_field uses the same wrapper as input but only with attribute components

closes #938 #823
Merge pull request #942 from plataformatec/issue-938

input_field uses the same wrapper as input but only with attribute components